/*
* Copyright (c) 2022, Ben Abraham <ben.d.abraham@gmail.com>
*
* SPDX-License-Identifier: BSD-2-Clause
*/
#include <AK/String.h>
#include <LibJS/Runtime/Realm.h>
#include <LibWeb/Bindings/MainThreadVM.h>
#include <LibWeb/Bindings/WorkerWrapper.h>
#include <LibWeb/DOM/ExceptionOr.h>
#include <LibWeb/HTML/Scripting/Environments.h>
#include <LibWeb/HTML/Worker.h>
#include <LibWeb/HTML/WorkerDebugConsoleClient.h>
namespace Web::HTML {
// https://html.spec.whatwg.org/multipage/workers.html#dedicated-workers-and-the-worker-interface
Worker::Worker(FlyString const& script_url, WorkerOptions const options, DOM::Document& document)
: m_script_url(script_url)
, m_options(options)
, m_document(&document)
, m_custom_data()
, m_worker_vm(JS::VM::create(adopt_own(m_custom_data)))
, m_interpreter(JS::Interpreter::create<JS::GlobalObject>(m_worker_vm))
, m_interpreter_scope(*m_interpreter)
, m_execution_context(m_worker_vm->heap())
, m_implicit_port(MessagePort::create())
{
}
// https://html.spec.whatwg.org/multipage/workers.html#dom-worker
DOM::ExceptionOr<NonnullRefPtr<Worker>> Worker::create(FlyString const& script_url, WorkerOptions const options, DOM::Document& document)
{
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Creating worker with script_url = {}", script_url);
// Returns a new Worker object. scriptURL will be fetched and executed in the background,
// creating a new global environment for which worker represents the communication channel.
// options can be used to define the name of that global environment via the name option,
// primarily for debugging purposes. It can also ensure this new global environment supports
// JavaScript modules (specify type: "module"), and if that is specified, can also be used
// to specify how scriptURL is fetched through the credentials option.
// FIXME: 1. The user agent may throw a "SecurityError" DOMException if the request violates
// a policy decision (e.g. if the user agent is configured to not allow the page to start dedicated workers).
// Technically not a fixme if our policy is not to throw errors :^)
// 2. Let outside settings be the current settings object.
auto& outside_settings = document.relevant_settings_object();
// 3. Parse the scriptURL argument relative to outside settings.
auto url = document.parse_url(script_url);
// 4. If this fails, throw a "SyntaxError" DOMException.
if (!url.is_valid()) {
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Invalid URL loaded '{}'.", script_url);
return DOM::SyntaxError::create("url is not valid");
}
// 5. Let worker URL be the resulting URL record.
// 6. Let worker be a new Worker object.
auto worker = adopt_ref(*new Worker(script_url, options, document));
// 7. Let outside port be a new MessagePort in outside settings's Realm.
auto outside_port = MessagePort::create();
// 8. Associate the outside port with worker
worker->m_outside_port = outside_port;
// 9. Run this step in parallel:
// 1. Run a worker given worker, worker URL, outside settings, outside port, and options.
worker->run_a_worker(url, outside_settings, outside_port, options);
// 10. Return worker
return worker;
}
// https://html.spec.whatwg.org/multipage/workers.html#run-a-worker
void Worker::run_a_worker(AK::URL& url, EnvironmentSettingsObject& outside_settings, MessagePort& outside_port, WorkerOptions const options)
{
// 1. Let is shared be true if worker is a SharedWorker object, and false otherwise.
// FIXME: SharedWorker support
auto is_shared = false;
auto is_top_level = false;
// 2. Let owner be the relevant owner to add given outside settings.
// FIXME: Support WorkerGlobalScope options
if (!is<HTML::WindowEnvironmentSettingsObject>(outside_settings))
TODO();
// 3. Let parent worker global scope be null.
// 4. If owner is a WorkerGlobalScope object (i.e., we are creating a nested dedicated worker),
// then set parent worker global scope to owner.
// FIXME: Support for nested workers.
// 5. Let unsafeWorkerCreationTime be the unsafe shared current time.
// 6. Let agent be the result of obtaining a dedicated/shared worker agent given outside settings
// and is shared. Run the rest of these steps in that agent.
// NOTE: This is effectively the worker's vm
// 7. Let realm execution context be the result of creating a new JavaScript realm given agent and the following customizations:
// FIXME: Perform the full steps for 'create a new JavaScript realm'
// https://html.spec.whatwg.org/multipage/webappapis.html#creating-a-new-javascript-realm
m_worker_realm = JS::Realm::create(m_worker_vm);
// 7a. For the global object, if is shared is true, create a new SharedWorkerGlobalScope object.
// 7b. Otherwise, create a new DedicatedWorkerGlobalScope object.
// FIXME: Proper support for both SharedWorkerGlobalScope and DedicatedWorkerGlobalScope
if (is_shared)
TODO();
// FIXME: Make and use subclasses of WorkerGlobalScope, however this requries JS::GlobalObject to
// play nicely with the IDL interpreter, to make spec-compliant extensions, which it currently does not.
m_worker_scope = m_worker_vm->heap().allocate_without_global_object<JS::GlobalObject>();
m_worker_scope->initialize_global_object();
m_console = adopt_ref(*new WorkerDebugConsoleClient(m_worker_scope->console()));
m_worker_scope->console().set_client(*m_console);
// FIXME: This should be done with IDL
u8 attr = JS::Attribute::Writable | JS::Attribute::Enumerable | JS::Attribute::Configurable;
m_worker_scope->define_native_function(
"postMessage", [this](auto& vm, auto&) {
// This is the implementation of the function that the spawned worked calls
// https://html.spec.whatwg.org/multipage/workers.html#dom-dedicatedworkerglobalscope-postmessage
// The postMessage(message, transfer) and postMessage(message, options) methods on DedicatedWorkerGlobalScope
// objects act as if, when invoked, it immediately invoked the respective postMessage(message, transfer) and
// postMessage(message, options) on the port, with the same arguments, and returned the same return value
auto message = vm.argument(0);
// FIXME: `transfer` not support by post_message yet
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Inner post_message");
// FIXME: This is a bit of a hack, in reality, we should m_outside_port->post_message and the onmessage event
// should bubble up to the Worker itself from there.
auto& event_loop = get_vm_event_loop(m_document->realm().vm());
event_loop.task_queue().add(HTML::Task::create(HTML::Task::Source::PostedMessage, nullptr, [this, message]() mutable {
MessageEventInit event_init {};
event_init.data = message;
event_init.origin = "<origin>";
dispatch_event(MessageEvent::create(HTML::EventNames::message, event_init));
}));
return JS::js_undefined();
},
2, attr);
// FIXME: This is because I don't know all the libraries well enough to properly setup the environment to spec
// let alone making it a parallel implementation.
m_execution_context.current_node = nullptr;
m_execution_context.this_value = m_worker_scope;
m_execution_context.function_name = "(global execution context)"sv;
m_execution_context.lexical_environment = &m_worker_realm->global_environment();
m_execution_context.variable_environment = &m_worker_realm->global_environment();
m_execution_context.realm = m_worker_realm;
m_worker_vm->push_execution_context(m_execution_context, *m_worker_scope);
m_worker_realm->set_global_object(*m_worker_scope, m_worker_scope);
// 8. Let worker global scope be the global object of realm execution context's Realm component.
// NOTE: This is the DedicatedWorkerGlobalScope or SharedWorkerGlobalScope object created in the previous step.
// 9. Set up a worker environment settings object with realm execution context,
// outside settings, and unsafeWorkerCreationTime, and let inside settings be the result.
m_inner_settings = WorkerEnvironmentSettingsObject::setup(*m_document, m_execution_context);
// 10. Set worker global scope's name to the value of options's name member.
// FIXME: name propery requires the SharedWorkerGlobalScope or DedicatedWorkerGlobalScope child class to be used
// 11. Append owner to worker global scope's owner set.
// FIXME: support for 'owner' set on WorkerGlobalScope
// 12. If is shared is true, then:
if (is_shared) {
// FIXME: Shared worker support
// 1. Set worker global scope's constructor origin to outside settings's origin.
// 2. Set worker global scope's constructor url to url.
// 3. Set worker global scope's type to the value of options's type member.
// 4. Set worker global scope's credentials to the value of options's credentials member.
}
// 13. Let destination be "sharedworker" if is shared is true, and "worker" otherwise.
// 14. Obtain script by switching on the value of options's type member:
// classic: Fetch a classic worker script given url, outside settings, destination, and inside settings.
// module: Fetch a module worker script graph given url, outside settings, destination, the value of the
// credentials member of options, and inside settings.
if (options.type != "classic") {
dbgln_if(WEB_WORKER_DEBUG, "Unsupported script type {} for LibWeb/Worker", options.type);
TODO();
}
ResourceLoader::the().load(
url,
[this, is_shared, is_top_level, url, &outside_port](auto data, auto&, auto) {
// In both cases, to perform the fetch given request, perform the following steps if the is top-level flag is set:
if (is_top_level) {
// 1. Set request's reserved client to inside settings.
// 2. Fetch request, and asynchronously wait to run the remaining steps
// as part of fetch's process response for the response response.
// Implied
// 3. Set worker global scope's url to response's url.
// 4. Initialize worker global scope's policy container given worker global scope, response, and inside settings.
// FIXME: implement policy container
// 5. If the Run CSP initialization for a global object algorithm returns "Blocked" when executed upon worker
// global scope, set response to a network error. [CSP]
// FIXME: CSP support
// 6. If worker global scope's embedder policy's value is compatible with cross-origin isolation and is shared is true,
// then set agent's agent cluster's cross-origin isolation mode to "logical" or "concrete".
// The one chosen is implementation-defined.
// FIXME: CORS policy support
// 7. If the result of checking a global object's embedder policy with worker global scope, outside settings,
// and response is false, then set response to a network error.
// FIXME: Embed policy support
// 8. Set worker global scope's cross-origin isolated capability to true if agent's agent cluster's cross-origin
// isolation mode is "concrete".
// FIXME: CORS policy support
if (!is_shared) {
// 9. If is shared is false and owner's cross-origin isolated capability is false, then set worker
// global scope's cross-origin isolated capability to false.
// 10. If is shared is false and response's url's scheme is "data", then set worker global scope's
// cross-origin isolated capability to false.
}
}
if (data.is_null()) {
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Failed to load {}", url);
return;
}
// Asynchronously complete the perform the fetch steps with response.
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Script ready!");
auto script = ClassicScript::create(url.to_string(), data, *m_inner_settings, AK::URL());
// NOTE: Steps 15-31 below pick up after step 14 in the main context, steps 1-10 above
// are only for validation when used in a top-level case (ie: from a Window)
// 15. Associate worker with worker global scope.
// FIXME: Global scope association
// 16. Let inside port be a new MessagePort object in inside settings's Realm.
auto inside_port = MessagePort::create();
// 17. Associate inside port with worker global scope.
// FIXME: Global scope association
// 18. Entangle outside port and inside port.
outside_port.entangle_with(*inside_port);
// 19. Create a new WorkerLocation object and associate it with worker global scope.
// 20. Closing orphan workers: Start monitoring the worker such that no sooner than it
// stops being a protected worker, and no later than it stops being a permissible worker,
// worker global scope's closing flag is set to true.
// FIXME: Worker monitoring and cleanup
// 21. Suspending workers: Start monitoring the worker, such that whenever worker global scope's
// closing flag is false and the worker is a suspendable worker, the user agent suspends
// execution of script in that worker until such time as either the closing flag switches to
// true or the worker stops being a suspendable worker
// FIXME: Worker suspending
// 22. Set inside settings's execution ready flag.
// FIXME: Implement worker settings object
// 23. If script is a classic script, then run the classic script script.
// Otherwise, it is a module script; run the module script script.
auto result = script->run();
// 24. Enable outside port's port message queue.
outside_port.start();
// 25. If is shared is false, enable the port message queue of the worker's implicit port.
if (!is_shared)
m_implicit_port->start();
// 26. If is shared is true, then queue a global task on DOM manipulation task source given worker
// global scope to fire an event named connect at worker global scope, using MessageEvent,
// with the data attribute initialized to the empty string, the ports attribute initialized
// to a new frozen array containing inside port, and the source attribute initialized to inside port.
// FIXME: Shared worker support
// 27. Enable the client message queue of the ServiceWorkerContainer object whose associated service
// worker client is worker global scope's relevant settings object.
// FIXME: Understand....and support worker global settings
// 28. Event loop: Run the responsible event loop specified by inside settings until it is destroyed.
},
[](auto&, auto) {
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: HONK! Failed to load script.");
});
}
// https://html.spec.whatwg.org/multipage/workers.html#dom-worker-terminate
DOM::ExceptionOr<void> Worker::terminate()
{
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Terminate");
return {};
}
// https://html.spec.whatwg.org/multipage/workers.html#dom-worker-postmessage
void Worker::post_message(JS::Value message, JS::Value)
{
dbgln_if(WEB_WORKER_DEBUG, "WebWorker: Post Message: {}", message.to_string_without_side_effects());
// 1. Let targetPort be the port with which this is entangled, if any; otherwise let it be null.
auto& target_port = m_outside_port;
// 2. Let options be «[ "transfer" → transfer ]».
// 3. Run the message port post message steps providing this, targetPort, message and options.
target_port->post_message(message);
}
JS::Object* Worker::create_wrapper(JS::GlobalObject& global_object)
{
return wrap(global_object, *this);
}
#undef __ENUMERATE
#define __ENUMERATE(attribute_name, event_name) \
void Worker::set_##attribute_name(Optional<Bindings::CallbackType> value) \
{ \
set_event_handler_attribute(event_name, move(value)); \
} \
Bindings::CallbackType* Worker::attribute_name() \
{ \
return event_handler_attribute(event_name); \
}
ENUMERATE_WORKER_EVENT_HANDLERS(__ENUMERATE)
#undef __ENUMERATE
} // namespace Web::HTML